There is known a power transmission line fault locating system of the surge-receiving type wherein a master station and a slave station merely independently receive surges and one or the other calculates the difference between the surge receiving times based on a synchronization signal via a communication network of a grounding system so as to locate the point where the surge occurred. However this system can only locate the point where the surge occurred and can not discriminate what kind of surge occurred.
In this conventional system, the kind of fault is detected by a protective relay provided in the substation separately from the fault locating system. Information based on the detection by the protective relay is displayed by a display unit near the protective relay in the substation or is transferred via the communication network to the sites where the information is required.
In many cases, however, the sites are provided with the information, they require by a phone call from a person at the substation or the like. As a result, the sites often do not receive the information promptly, which is likely to delay the start of the restoration work.
Furthermore, the protective relay must be of large capacity and is subject to extremely large loads. What is more, it can not detect inductive strikes.